Storage system, management server, and method of managing application thereof

ABSTRACT

In a storage system having a plurality of disk array devices connected through a network to a host for running an application, and a management server for monitoring the disk array devices, the disk array device includes a physical disk error detecting unit for detecting an error in a physical disk. Meanwhile, the management server stores a corresponding relationship among the application, a logical volume used by the application, and the physical disk corresponding to the logical volume. Moreover, the management server includes an application detecting unit for detecting the application using the logical volume corresponding to the physical disk with the error according to the corresponding relationship when the physical disk error detecting unit of the disk array device detects the error in the physical disk.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application claims priority upon Japanese Patent ApplicationNo. 2002-150145 filed on May 24, 2002, which is herein incorporated byreference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a storage system, a management server,and a method of managing an application thereof.

2. Description of the Related Art

A host uses a plurality of disk array devices as external storagedevices upon operation of an application. A disk array device includes aplurality of disks. To be more precise, the host is connected to thedisk array devices through a storage area network (SAN), whereby dataare distributed to a logical volume (LU) composed of the plurality ofdisks to be stored.

As a technology for enhancing fault tolerance of such a disk arraydevice, for example, Japanese Patent Application Laid-open PublicationNo. 2000-305720 discloses a technology for predicting a failure of adisk. Meanwhile, according to Japanese Patent Application Laid-openPublication No. 2001-167035, a client on a network is monitored by usinga WWW browser in order to enhance fault tolerance of the disk arraydevice. Moreover, Japanese Patent Application Laid-open Publication No.Hei11-24850 discloses a technology for recovering data contained in afailed drive such that the data belonging to a volume of a highestfrequency of failures first, then the recovery is attempted according tothe failure frequency Furthermore, Japanese Patent Application Laid-openPublication No. 2000-20245 discloses a technology for automaticallyconfiguring a disk drive connected to a controller.

In general, a disk array device utilizes a “Redundant Array ofInexpensive Disks” (RAID) technology to prevent data loss or system downof a host. Parity and error correction data are added to data to bewritten, and the data are distributed to a plurality of disks forstorage. In this way, it is possible to restore correct data using theparity even if one of the disks is out of order.

However, execution of data restoring processing, when a disk is out oforder, incurs performance degradation of operation of an application ascompared to a normal condition. Moreover, if a spare disk exists whenthe drive is blocked, the blocked disk will be restored by using thespare disk. Execution of such restoring processing also incursperformance degradation of an application as compared to a normalcondition.

Nevertheless, such restoring processing has been executed withoutnotifying a user. Accordingly, the user would not recognize that thecause of the performance degradation of the application is due to thedata restoring processing and has occasionally sought other causes.

In addition, when the drive is blocked, a system administrator receivingsuch warning has had difficulty predicting influence to the performancedegradation of the application.

SUMMARY OF THE INVENTION

In a storage system having a plurality of disk array devices connectedto a host, which runs an application, through a network, and amanagement server for monitoring each drive installed in the disk arraydevices, the disk array device includes a physical disk error detectingunit for detecting an error in a physical disk. The management serverstores a corresponding relationship among the application, a logicalvolume used by the application, and the physical disk corresponding tothe logical volume. The management server includes an applicationdetecting unit for detecting the application using the logical volumecorresponding to the physical disk with the error according to thecorresponding relationship when the physical disk error detecting unitof the disk array device detects the error in the physical disk.

Note that the management server may be disposed inside the disk arraydevice. Moreover, it is also possible to provide a configuration where amanagement server unit having functions of the management server isincorporated into the disk array device. In other words, the term“management server” also includes the concept of the “management serverunit”.

The present invention can suppress performance degradation of anapplication.

Features and objects of the present invention other than the above willbecome clear by reading the description of the present specificationwith reference to the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present invention and theadvantages thereof, reference is now made to the following descriptiontaken in conjunction with the accompanying drawings wherein:

FIG. 1 is a block diagram showing an entire configuration of a storagesystem, which is one of the embodiments of the present invention;

FIG. 2 is a conceptual diagram showing an aspect of distributed datastorage according to one of the embodiments of the present invention;

FIG. 3 is a schematic diagram showing a screen for monitoringperformance of a disk array device according to one of the embodimentsof the present invention;

FIG. 4 is a block diagram showing functions of a management serveraccording to the embodiments of the present invention;

FIG. 5 is a schematic diagram showing a screen for monitoringperformances of the disk array device according to the embodiments ofthe present invention;

FIG. 6 is a flowchart showing processing upon occurrence of a diskfailure according to the embodiments of the present invention; and

FIG. 7 is a schematic diagram showing an aspect of switching a drive towhich an application gains access, from a main drive to a sub drive.

DETAILED DESCRIPTION OF THE INVENTION

At least the following matters will be made clear by the explanation inthe present specification and the description of the accompanyingdrawings.

A management server may include application notifying unit that notifiesa user terminal of information concerning the application detected bythe application detecting unit.

The corresponding relationship stored by the management server containssettings on priority of execution of a job of an application. Themanagement server may include application processing capabilityallocating unit for allocating a processing capability of theapplication according to the priority of execution of the job of theapplication which uses the physical disk with the error when thephysical disk error detecting unit of the disk array device detects theerror in the physical disk.

The management server may give higher priority to execution of the jobof the application using the physical disk with the error when thephysical disk error detecting unit of the disk array device detects theerror in the physical disk.

The application processing capability allocating unit of the managementserver may allocate the processing capability of the applicationaccording to operation input of a user.

The management server may include at least the application detected bythe application detecting unit, the disk array device used by theapplication, and application information displaying unit for displayingapplication information concerning the processing capability allocatedto the application on a screen of a display unit.

The disk array device may be capable of executing mirroring, and themanagement server may include mirror disk switching unit for setting amirror disk for the application to use, when the physical disk errordetecting unit of the disk array device detects an error in the physicaldisk.

Herein, the expression “capable of executing mirroring” refers to astate where the disk array device supports “RAID-1” (“mirror” or“mirroring”) as a RAID level.

The disk array device may include the physical disk error detecting unitfor detecting an error in the physical disk, and the management servermay include internal copy switching unit for executing internal copyprocessing by allocating a new logical volume to an unused disk area (anempty disk) in the disk array device, when the physical disk errordetecting unit of the disk array device detects an error in the physicaldisk, and thereby setting the new logical volume for the application touse.

FIG. 1 shows an entire configuration of a storage system according tothe present embodiment. A plurality of hosts 10 are connected to aplurality of disk array devices (also referred to as “disk subsystems”)20 through a storage area network (SAN) 40. An application is installedin each of the hosts (computers) 10 by a user, and the hosts 10 sharethe plurality of disk array devices 20 as external storage devices ofdata required for running this application. Alternatively, there is alsoa case where the application itself is installed in the disk arraydevices 20. That means the scope of the present invention shall not belimited by which directory the application installed in. A managementserver 30 can be connected to the plurality of hosts 10 and to theplurality of disk array devices 20 through a different local areanetwork (LAN) 50 of SAN 40. Alternatively, the management server 30 maybe directly connected to the SAN 40.

A host agent 11 is installed in each host 10. The host agent 11 isactivated when a request for acquiring system configuration informationto the respective disk array devices 20 is made due to operation inputto the management server 30 by a system administrator or due to an eventsuch as a failure of the disk array device 20. In order to acquire “hostlogical configuration information” on an operation system (OS) of thehost 10 dominating the host agent 11, the host agent 11 issues a commandto a logical volume of the disk array device 20, which is accessible bythe host 10 of its own, to receive an access path.

The host agent 11 utilizes the OS, a database, and an applicationinterface of upper middleware. Thereby acquires a name of a file storedin the logical volume, a capacity of the file, and the location in afile system which the file belongs to.

Each of the disk array devices 20 includes an external connectioninterface 21. Each of the disk array devices 20 notifies the managementserver 30 of the configuration information, the performance and thecontaining data of its own through the external connection interface 21.Moreover, the disk array device 20 detects an error such as a failure ofa physical disk of its own and notifies the management server 30.Alternatively, the management server 30 may gain access to the diskarray device 20 and collect the configuration information, theperformance, the data, and information concerning the failure thereof.In another embodiment where the management server 30 is connected onlyto the SAN 40, similar information as described above is sent orcollected directly to the management server 30 by using a SAN interfacefor the management server 30, instead of using the external connectioninterface 21.

The disk array device 20 incorporates a control board (a controller)therein. The disk array device 20 is controlled by a microprogram(physical disk error detecting unit) which runs on a processor (CPU,physical disk error detecting unit) implemented in this controller.

By this microprogram in operation, it is possible to detect errorsincluding failures of the physical disk of the disk array device 20,such as an I/O error. In other words, it is possible to predictperformance degradation of the application by detecting failures anderrors in the physical disk. The method of detecting such errors will bedescribed specifically as follows. For example, data control of the diskarray device 20 is performed by the control board (controller) of thedisk array device. The microprogram runs on the CPU implemented on thiscontroller and controls the device. When there is a request from anupper layer (such as a host) for reading the data, the microprogramperforms the control so as to read the data. Normally, data reading isperformed via a cache, and in the case where the data do not exist inthe cache, the data are read from the drive and stored in the cache ordirectly sent to the upper layer. In the RAID, the data to be read arenormally stored in the drives in a distributed manner. Moreover, theRAID adopts the mode of regenerating data from parity even if part ofthe data cannot be read. In the event of reading the data, the controlof reading the distributed data is performed by the microprogram. If apart of the data cannot be read, the control of reading the parity forrestoring the data is performed by the microprogram. Therefore, theprocessing for performing data restoration from the parity is executedby the microprogram. Accordingly, the frequency the restoration can beperceived by the microprogram. For example, the microprogram can alsoperceive the frequency of failures of when accessing each drive. Thus,it is possible to predict an occurrence of an error such as a failure ina certain drive if the failures of when accessing exceed a giventhreshold (such as a number of simple cumulative failures or a number ofcumulative failures) Such processing is adopted not only for readingprocessing, but also for writing processing similarly.

FIG. 2 is a conceptual diagram showing an aspect of distributed datastorage. As shown in FIG. 2, the disk array device 20 includes aplurality of drives. In the example shown in FIG. 2, five disks markedby A to E. are installed. Moreover, a logical unit (LU) is defined inthese five disk drives. This logical unit is regarded as one logicalvolume from the outside. For example, a logical volume (LU0) includesfour drives marked by A, B, C and D. In the disk array device 20, at aRAID level referred to as “RAID-5”, the data are distributed and writtenacross the drives (physical disks) HDD-A to HDD-E as in D1, D2and D3.Further, parity P1is also written. In this way, the drives HDD-A toHDD-E, which store the distributed data D1, D2 and D3and the parity P1,collectively construct the logical volume (logical unit) LU0 or alogical volume LU1.

Meanwhile, as shown in the corresponding table in FIG. 3, regarding thedisk array device 20, the management server 30 stores correspondingrelationships among applications AP-A to AP-E run on the host 10, thelogical volumes LU0 and LU1 used by the applications, and the physicaldisks HDD-A to HDD-E corresponding to the logical volumes LU0 and LU1.

The corresponding relationships as shown in FIG. 3 may be referenced notonly by the system administrator who uses the management server 30, butalso by a user who uses the applications through the hosts, with a webscreen or the like.

The management server 30 has a computer system (application detectingunit, mirror disk switching unit, internal copy switching unit,application notifying unit, application processing capability allocatingunit, and application information displaying unit). FIG. 4 is a blockdiagram showing the functions of this management server 30. Themanagement server 30 includes a user management layer 31, an objectmanagement layer 32, an agent management layer 33, and an interfacelayer 34. The object management layer 32 includes a database foraccumulating configuration information concerning the respective diskarray devices 20. As described above, the corresponding relationshipsamong the applications, the logical volumes and the physical disks arestored in this database. The interface layer 34 includes a subsysteminterface 341 and a host interface 342.

A plurality of user terminals A to C are connected to the managementserver 30 through the user management layer 31. Moreover, the pluralityof disk array devices 20 are connected to the management server 30through the subsystem interface 341. Furthermore, the hosts 10 areconnected to the management server 30 through the host interface 342.

The user management layer 31 manages the user terminals A to C. Herein,the system administrator is also included as one of the users. Theobject management layer 32 acquires information concerning theconfigurations, performances and errors such as failures of therespective disk array devices 20 as well as information concerning otherevents, and stores the information in the database. To be more precise,the information to be stored in this database includes: settingsconcerning internal access paths and the logical volumes of therespective disk array devices 20, capacities, access authorization, anddata transfer of the respective logical volumes; settings concerningdata copy among the respective disk array devices 20; settingsconcerning the performances and control of the respective disk arraydevices 20; and settings of methods of acquiring and maintaining theperformance data, abnormality such as failures, and the configurationinformation of events in the respective disc devices 20 by useroperations of the respective disk array devices.

Although only one management server 30 is shown in FIG. 1, it ispossible to use a plurality of management servers 30. Moreover, themanagement server 30 may be installed inside the disk array device 20.Furthermore, it is also possible to adopt a configuration where amanagement server unit having the functions of the management server 30is incorporated into the disk array device 20. In other words, the term“management server” also may be interpreted as the “management serverunit”. Meanwhile, the management server unit maybe located in a positionphysically distant from the disk array device 20.

The management server 30 makes periodic inquiries to the respective diskarray devices 20 and acquires the information concerning the events ofabnormality such as failures. Alternatively, the information concerningthe events such as failures or maintenance detected by the respectivedisk array devices 20 is notified to the agent management layer 33 ofthe management server 30 through the subsystem interface 341.

Upon notification of the events such as failures, the agent managementlayer 33 notifies the object management layer 32 by using an interruptfunction. The management server 30 recognizes a status change of thedisk array device 20 by the object management layer 32 that has receivedsuch notification. After recognizing this event, the management server30 acquires the configuration information of the disk array device 20and updates the information in the database.

As shown in a schematic diagram in FIG. 5, a screen for monitoring theperformances of the disk array devices is displayed on a display unit ofthe management server 30 by a graphical user interface (GUI). Theinformation displayed on this screen is based on the correspondingrelationships in FIG. 3 as previously described. As shown in FIG. 5,description will be firstly given regarding an A system as the“application”. The A system uses a disk array device “D-B”. A “drivestatus” of this disk array device D-B is indicated as “OK”, in otherwords, there are no abnormality such as a breakdown or a failuretherein. Priority of execution of a job (“job priority”) of this Asystem is set to “B” which is lower than “A”, and allocation of aprocessing capability is set to a level “10”. A field for “other status”is blank since the “drive status” is “OK” and indicates that no specialmeasures are taken.

Next, description will be given regarding a B system as the“application”. The B system uses a disk array device “D-B”. The “drivestatus” of the disk array device D-B is indicated as “failure”. Priorityof execution of a job (“job priority”) of this B system is set to “A”which is higher than “B”, thus the priority is set higher than theabove-described A system. Moreover, allocation of a processingcapability regarding this B system is set to a level “10”. A field for“other status” is indicated as “mirror in use” since “drive status” is“failure”, and shows that data on a mirror disk are used as a primary(main) I/O.

Next, description will be given with reference to a flowchart in FIG. 6,regarding countermeasure processing by the management server in the casewhere a failure occurs in the disk (a drive or a physical disk).Firstly, when an error in the physical disk such as an I/O error in thedrive is detected (S10), judgment is made on whether a mirror driveexists (S20). If the mirror drive exists (S20: YES), the access drivewhich application uses is switched from the main drive to a sub drive asshown in FIG. 7 (S30). In this way, with respect to the failure of disk,it is possible to eliminate influence to the operation of theapplication, attributable to an increase in load of processing due todata restoration from the parity. Subsequently, the occurrence of thefailure and the state of switching the access drive are notified to thesystem administrator (S40). For such notification, as shown in FIG. 5,an appropriate method such as displaying on the displaying unit of themanagement server is used. In addition, it is also possible to notifythe information shown in FIG. 5 to the user who uses the applicationthrough the host, with a Web screen or the like. Thereafter, if thefailed drive is recovered or restored by a replacement, then the accessdrive is set back to the original drive, which is the normal drive (S50to S60).

On the contrary, if the mirror drive does not exist (S20: NO), as atemporary processing, judgment is made on whether it is possible tocreate a mirror (an internal copy or a synchronous copy area) internally(S70). If it is possible to create the internal copy (S70: YES), a newlogical volume is created in another drive without failure (S80). Thenew logical volume, which is internally copied, is set to the accessdrive which the application uses (S90). Subsequently, the occurrence ofthe failure and the state of switching the access drive are notified tothe system administrator (S100). For such notification, as shown in FIG.5, an appropriate method such as displaying on the displaying unit ofthe management server is used. In addition, it is also possible tonotify the information shown in FIG. 5 to the user who uses theapplication through the host, with a Web screen or the like. Thereafter,when the failed drive is recovered or restored by a replacement, theaccess drive is set back to the original drive, which is the normaldrive, and the internal copy is deleted (S110 to S120).

Meanwhile, if it is impossible to create the internal copy (S70: NO), itis possible to use another disk array device. Based on theabove-described corresponding table in FIG. 3, the logical volumecorresponding to the failed drive is retrieved (S130). Thereafter, as aresult of the retrieval, the application using the acquired logicalvolume is detected (S140). Subsequently, the risk of performancedegradation of the detected application is notified to the systemadministrator (S150). For such notification, as shown in FIG. 5, anappropriate method such as displaying on the displaying unit of themanagement server is used. In addition, it is also possible to notifythe information shown in FIG. 5 to the user who uses the applicationthrough the host, with a Web screen or the like.

Next, as shown in the above-described information displayed on thescreen in FIG. 5, countermeasure processing for load distribution of theapplication having the risk of the performance degradation is executedaccording to the job priority. For example, as shown in FIG. 5, if thereis a risk of performance degradation of the B system as the applicationhaving the higher priority “A” and the mirror drive is not used underthat status, the allocation of the processing capability is increasedfrom “10” to “15”, so that the performance of the application can bemaintained without being influenced by the drive failure. Herein, anincrease in the allocation of the processing capability is equivalent toan increase in an allocation rate of the CPU resources.

Moreover, a similar effect can be exerted by raising the job priority ofthe application (S160). Alternatively, it is also possible to relativelyavoid a decrease in the processing capability of the application havingthe higher priority “A” by reducing the allocation of the processingcapability at the A system side as the application having the lowerpriority “B”.

Such allocation of the processing capabilities and settings of the jobpriority can be performed through the screen displayed on the displayunit in FIG. 5 by the GUI. Thereafter, when the failed drive isrecovered or restored by a replacement, the allocation of the processingcapabilities and the job priority of the applications are set back tothe original states (S170 to S180).

As for another embodiment, it is also possible to distribute the load byeach logical volume unit, in the state without failures such as errorsin a disk (drive). This is performed by monitoring a usage status of theapplication and an access status regarding the respective logicalvolumes. In this way, it is possible to prevent an event such asperformance degradation of a certain logical volume.

The embodiments of the present invention can exert the followingeffects:

The management server stores corresponding relationships among theapplications, the logical volumes used by the applications, and thephysical disks corresponding to the logical volumes. Thus, it ispossible to detect the application which may be influenced by the errorin the physical disk and to predict the performance degradation thereof.Based on this prediction, it is possible to suppress the performancedegradation or an abnormal termination.

The management server notifies the user terminal of informationconcerning the application which may be influenced by the error in thephysical disk. In this way., it is possible to advise the user on therisk of the performance degradation of the application.

The priority of execution of the job of the application is set in thecorresponding relationship stored by the management server. Themanagement server allocates the processing capability of the applicationaccording to the priority of execution of the job of the applicationwhich uses the physical disk with the error. In this way, it is possibleto control the load of the application.

The management server gives higher priority to execution of the job ofthe application which uses the physical disk with the error. In thisway, it is possible to suppress the performance degradation of theapplication.

The management server allocates the processing capability of theapplication according to operation input of the user. The user cancontrol the load of the application which may be influenced by the errorin the physical disk.

The management server displays the information concerning theapplications, the disk array devices used by the applications, and theprocessing capabilities allocated to the applications on the screen ofthe display unit. In this way, the user can monitor the logical volumeand the application which may be influenced by the error in the physicaldisk, and the processing capability allocated to the application on thedisplay unit.

Upon detection of the error in the physical disk, the management serversets the corresponding mirror disk to which the application uses. Inthis way, it is possible to prevent the performance degradation of theapplication beforehand.

Upon detection of the error in the physical disk, the management serverallocates a new logical volume to an unused disk area in the disk arraydevice and executes internal copy processing, whereby the managementserver sets the new logical volume to which the application uses. Inthis way, it is possible to prevent the performance degradation of theapplication beforehand.

Although the present invention has been described above based on theembodiments, it is to be noted that the present invention shall not belimited to the embodiments stated herein, and that various modificationscan be made without departing from spirit of the invention.

1. A storage system comprising; a plurality of disk array devicesconnected through a network to at least one host for running a pluralityof applications and each disk array device having a plurality ofphysical disks a plurality of logical volumes relating to said physicaldisks, a cache memory temporarily storing data sent from the host to thelogical volumes, and a controller to transfer data to the physical disksvia the cache memory: and a management server configured to monitor saiddisk array devices, said management server being connected to said hostand said disk array devices, and to communicate management informationto said host and said disk array devices, wherein said disk arraydevices include a physical disk error detecting unit configured todetect an error in a physical disk of said physical disks: wherein saidmanagement server stores the management information including acorresponding relationship among identification of each of saidapplications, identification of at least one logical volumes used bysaid each application, and identification of at least one of saidphysical disks corresponding to said at least one logical volume, andwherein said management server includes an application detecting unitconfigured, when said physical disk error detecting unit of said diskarray devices identifies an error in said physical disk, to detect saidapplication using said logical volume corresponding to said physicaldisk, with the error according to said corresponding relationship storedin said management server.
 2. A storage system according to claim 1,wherein said management server includes an application notifying unitconfigured to notify a user terminal of information concerning saidapplication detected by said application detecting unit.
 3. A storagesystem according to claim 1, wherein said corresponding relationshipstored by said management server contains settings on priority ofexecution of a job of said application, and wherein said managementserver includes an application processing capability allocating unitconfigured 10 allocate a processing capability of said applicationaccording to said priority of execution of the job of said applicationwhich uses said physical disk with the error when said physical diskerror detecting unit of said disk array device detects the error in saidphysical disk.
 4. A storage system according to claim 3, wherein saidmanagement server gives higher priority to execution of said job of saidapplication which uses said physical disk with said error when saidphysical disk error detecting unit of said disk array device detectssaid error in said physical disk.
 5. A storage system according to claim3, wherein said application processing capability allocating unit ofsaid management server allocates the processing capability of saidapplication according to operation input of a user.
 6. A storage systemaccording to claim 1, wherein said management server at least includesapplications detected by said application detecting unit, said diskarray device used by said application, and an application informationdisplaying unit configured to display application information concerninga processing capability allocated to said application on a screen of adisplay unit.
 7. A management server for monitoring a plurality of diskarray devices connected through a network to at least one host forrunning a plurality of applications and each disk array device having aplurality of physical disks and a plurality of logical volumes relatingto said physical disks and for communicating management information tosaid host and said disk array devices, said management server beingconnected to said host and said disk array devices, said managementserver comprising: a physical disk error detecting unit configured todetect an error in a physical disk of said physical disks, wherein saidmanagement server stores the management information including acorresponding relationship among identification of each of saidapplications, identification of at least one logical volume used by saideach application, and identification of at least one of said physicaldisks corresponding to said at least one logical volume, and anapplication detecting unit configured, when said physical disk errordetecting unit of said disk array device identifies an error in saidphysical disk, to detect said application using a logical volumecorresponding to said physical disk with said error according to saidcorresponding relationship stored in said management server.
 8. Amanagement server according to claim 7, further comprising: anapplication notifying unit configured to notify a user terminal ofinformation concerning said application detected by said applicationdetecting unit.
 9. A management server according to claim 7, whereinsaid corresponding relationship contains settings on priority ofexecution of a job of said application, and wherein said managementserver further comprises an application processing capability allocatingunit configured to allocate a processing capability of said applicationaccording to said priority of execution of said job of said applicationwhich uses said physical disk with said error, when said physical diskerror detecting unit of said disk army device detects said error in saidphysical disk.
 10. A management server according to claim 9, whereinhigher priority is given for execution at said job of said applicationusing said physical disk with said error when said physical disk errordetecting unit of said disk array device detects said error in saidphysical disk.
 11. A management server according to claim 9, whereinsaid application processing capability allocating unit allocates theprocessing capability of said application according to operation inputof a user.
 12. A management server according to claim 7 furthercomprising at least: applications detected by said application detectingunit, said disk array device used by said application, and anapplication information displaying unit configured to displayapplication information concerning a processing capability allocated tosaid application on a screen of a display unit.
 13. A method of managingan application by a management server for monitoring a plurality of diskarray devices connected through a network to at least one host forrunning a plurality of applications and each disk array device having aplurality of physical disks and a plurality of logical volumes relatingto said physical disks, said management server being connected to saidhost and said disk array devices, said method comprising: storing bysaid management sever management information, including a correspondingrelationship among identification of each of said applications,identification of at least one logical volume used by said eachapplication, and identification of at least one of said physical diskscorresponding to said at least one logical volume; communicating by saidmanagement server the management information to said host and said diskarray devices; and detecting by said management server said applicationusing said logical volume corresponding to said physical disk with anerror according to said corresponding relationship stored by saidmanagement server when said disk array device identifies said error insaid physical disk.
 14. A method of managing an application according toclaim 13, wherein information concerning said detected application isnotified to a user terminal.
 15. A method of managing an applicationaccording to claim 14, wherein higher priority is given to execution ofsaid job of said application using said physical disk with said errorwhen said disk army device detects said error in said physical disk. 16.A method of managing an application according to claim 15, wherein theprocessing capability of said application is allocated according tooperation input of a user.
 17. A method of managing an applicationaccording to claim 13, wherein said corresponding relationship containssettings on priority of execution of a job of said application, andwherein a processing capability of said application is allocatedaccording to the priority of execution of said job of said applicationwhich uses said physical disk with said error when said disk arraydevice detects said error in said physical disk.
 18. A method ofmanaging an application according to claim 13, wherein at leastapplication information concerning said detected application, said diskarray device used by said application, and the processing capabilityallocated to said application are displayed on a screen of a displayunit.